1. Field of the Invention
The present invention pertains to devices and methods for the extraction, transportation and/or release of materials, such as may be used in connection with well-cleanout operations.
2. Description of the Related Art
Solid waste landfills often have gas wells to extract methane gas. Gas is extracted from the top of the well by applying suction to the well casing. Landfills also often have systems to remove liquids, called “leachate”, that collect in sumps at the bottom, on an impervious liner. The conventional leachate removal system often includes a “riser” pipe, similar in concept to a well casing. The riser pipe provides an open path for a pump to be lowered to the sump, for the pump's service lines, and for periodic removal of the pump.
These gas wells and riser pipes can be vertical, inclined, straight, curved, have multiple curves in more than one direction, be partially constricted and/or have uneven inside surfaces. Such wells may be constructed in this manner (e.g., at an angle of up to 60 degrees away from vertical) and, in addition, a gas well that initially was straight can become bent or curved into a circuitous path due to shifting of the landfill material. Such gas wells and riser pipes usually are between 6 inches and 24 inches in diameter, are made of steel or plastic pipe, and can be more than 300 feet deep. They often contain methane gas, a by-product of solid waste decomposition, which can be combustible or explosive when mixed with oxygen in the air and ignited. The temperature can reach 140 degrees Fahrenheit or more.
Such gas wells and riser pipes sometimes accumulate a mixture of liquid, sediment, sand, scale, rocks, floating items and/or debris (“Material”) that reduces or inhibits one's ability to extract the gas and/or pump the leachate by conventional means. When this problem becomes too severe, it often is necessary to abandon the well and drill a new one.
Accordingly, the present inventor has discovered that what is needed is a more efficient and cost-effective means for dealing with the accumulation of such Material. Toward this end, the present inventor has examined conventional cleanout tools used in other applications, but was unable to find any tool that would be appropriate or optimal for landfill-well cleanout.
For example, some conventional methods to clean water, oil or natural-gas wells utilize a pipe string that is relatively stiff. While this is appropriate in these applications, where the well has been drilled into the ground and therefore is relatively straight, such a pipe string generally cannot travel through casings that curve, bend, have partial restrictions, and/or have uneven inside surfaces. In addition, some of such conventional equipment has one or more valves that can stick or cause clogs, making the equipment ineffective and/or necessitating frequent service. Further, some of such conventional equipment requires the use of electricity within the well, which can spark and ignite the combustible methane if it were used for landfill-well cleanout.
Some existing methods to clean storm drains or sewers utilize suction, but such methods typically cannot suck such Materials or similar mixtures to the necessary height in connection with the foregoing problem concerning landfill-well cleanout.